Two position tool holder

ABSTRACT

A tool holder according to the present disclosure includes a spindle adapted to be mounted to a machine. Housing means is journaled by the spindle for movement between first and second angular positions. Mount means carried by the housing means supports a work tool, and drive means is provided for rotating the housing between the first and second angular positions. Clamp means is provided for preventing relative rotation of the housing and the spindle when the housing means is in either its first or second angular position. Preferably, the drive means includes a hydraulic actuator which may comprise a rotor attached to the housing and a piston disposed for reciprocal movement along the axis of the tool holder. Cam and cam follower means is provided for relative operation between the rotor and piston so that when the piston moves between first and second axial positions, the rotor is rotated to drive the housing between its first and second angular positions. Indexing means is provided for accurately indexing the first and second angular positions of the housing, which means comprises a set of stops.

United States Patent McCullough [451 July 1 l, 1972 [54) TWO POSITIONTOOL HOLDER 57 ABSTRACT Inventor? McCullough. COVina. Calif- A toolholder according to the present disclosure includes a spindle adapted tobe mounted to a machine. Housing means Asslsnee' Te Covma Cahf' isjoumaled by the spindle for movement between first and [22! Filed: Aug.13, I970 second angular positions. Mount means carried by the housing Ameans supports a work tool, and drive means is provided for Appl' 63'545rotating the housing between the first and second angular positions.Clamp means is provided for preventing relative 521 u.s.c|. .82/36A14/322 using and Spindle when musing [51 1 Int Cl i 823") 29/32 means isin either its first or second angular position. Preferably, the drivemeans includes a hydraulic actuator [58] Field 0! Search ..82/36 A,74/8l3, 822 which y comprise a rotor anached m the housing and a pistondisposed for reciprocal movement along the axis of the [$6] Re'mnmsCited tool holder. Cam and cam follower means is provided for rela-UNITED STATES PATEm-S tive operation between the rotor and piston sothat when the piston moves between first and second axial positions, the3,l62,064 12/1964 Musy ..74/822 rotor is rotated to drive the housingbetween its first and second angular positions. Indexing means isprovided for ac- FOREIGN PATENTS 0R APPLICATIONS curately indexing thefirst and second angular positions of the 495 577 8/1967 France ..82/36A Mush! which mm a [72,079 6/l967 Great Britain .....82/36 A 10 Chaim 9Drawing Primary Examiner-Leonidas Vlachos Attorney-Angus & Mon

PATENTEDJUL 1 1 m2 SHEET 2 OF 3 INVENTOR. JTUA R 7' MC CUL LOUGHP'ATE'N'TEDJuL n 1972 3,575,519

SHEET 30F 3 -ql l I IE/G. 9

h v INVENTOR. Q srwmr MOCULLOUGH A TTOR/VEYS.

TWO POSITION TOOL HOLDER This invention relates to tool holders, andparticularly to multi-position indexing tool holders such as aredesigned to fit on the cross slide of a lathe.

It is often desirable to utilize different work tools on a machine forsuccessive operations on a workpiece. For example, it is common to useone work tool for roughing" a workpiece to define its general shape,while another work tool may be used for finishing the workpiece.Heretofore, it has been the practice to position a work tool on themachine to rough work the workpiece and thereafter replace the work toolwith a finishing tool to finish the product. One disadvantage to such anarrangement has been that the machine has to be shut down to enable thework tool to be replaced thereby resulting in a shut down of operationresulting in lost time in the operation of the machine and the machinewas not used to its full capacity.

It is an object of the present invention to provide a tool holder towhich a plurality of work tools or the like may be fastened and whichselectively positions the tools in position for operating on aworkpiece.

Another object of the present invention is to provide a tool holderwherein a tool may be moved into and out of position for operating on aworkpiece and wherein the position of the tool is accurately indexed.

Another object of the present invention is to provide an indexing toolholder for moving a plurality of tools into and out of position foroperating on a workpiece, which tool holder provides means for clampingthe position of the tool holder in predetermined positions to preventundesired movement of the tool when in such position.

An indexing tool holder in accordance with the present inventioncomprises a spindle adapted to be mounted to a machine and a housingjoumaled to the spindle and capable of rotating about an axis betweenfirst and second angular positions. Means is provided for mounting toolsto the housing, and drive means is provided for rotating the housingbetween the first and second angular positions. Clamp means is providedfor preventing relative rotation of the housing when the housing is ineither its first or its second angular position.

The indexing tool holder according to the present invention providesmeans for supporting a tool which may be mounted to a machine. The toolholder is capable of moving the tool into and out of position foroperation on a workpiece. Several tools may be mounted to the toolholder so that one tool is moved out of position while a second tool ismoved into position for operation on a workpiece. The clamp means isoperable whenever a tool is in position for operation on a workpiece.

According to one feature of the present invention, the drive meansincludes piston means adapted to reciprocate between first and secondaxial positions, and cam and cam follower means are associated with thehousing and piston means to rotate the housing upon reciprocal movementof the piston means.

According to another feature of the present invention, indexing meanslimits the extent of rotational travel of the housing means, therebyaccurately defining the first and second angular position of thehousing.

According to another feature of the present invention, valve means isresponsive to the position of the piston means for operating the clampmeans.

According to yet another feature of the present invention, the pistonmeans and clamp means are hydraulically operated.

Yet another feature of the present invention resides in the provision ofa hydraulic circuit for operating the tool holder.

The above and other features of this invention will be more fullyunderstood from the following detailed description, and the accompanyingdrawings, in which:

FIG. 1 is a side view elevation partly in cutaway cross-section of anindexing tool holder in accordance with the presently preferredembodiment of the present invention;

FIGS. 2-7, inclusive, are section views of the tool holder taken atlines 2-2, 3-3, 44, 5-5, 6-6 and 77, respec tively in FIG. 1;

FIG. 8 is a bottom view of the tool holder taken at line 88 in FIG. 1;and

FIG. 9 is a schematic hydraulic and electric diagram of a hydraulic andelectric circuit for operating the tool holder.

Referring to the drawings, and particularly to FIGS. 1-8, inclusive,there is illustrated a tool holder 10 in accordance with the presentlypreferred embodiment of the present invention. Tool holder 10 includes astationary spindle 11 mounted by threaded fasteners 12 to a machineillustrated generally at 13. Spindle 11 includes a substantiallycylindrical shaft 14 having a central axis 15. Frusto-conical surface 16is disposed at the lower end of shaft 14 and extends outwardlytherefrom. Housing 17 includes dovetails 18 to which suitable worktools, such as cutting tools (not shown), may be fastened. By way ofexample, the tools may be fastened to brackets 19 which in turn may befastened to dovetails 18. Member 20 having a conical surface 21 isfastened to housing 17 and is adapted to clamp against frusto-conicalsurface 16 of spindle 11. Preferably, cavity 22 is provided betweenspindle 11 and housing 17, which cavity may act as a reservoir forlubricant. Seals 23 and 24 prevent leakage of lubricant from cavity 22and prevent contamination of the lubricant by foreign material.

Spindle 11 includes internal cylinder 25 which carries piston 26 havingan extended shaft portion 27. Seal 28 provides a fluid seal betweenopposite side of piston 26. Spindle 11 also includes a cylindrical bore32 in which valve spool 30 is fitted.

Valving means 29 includes a spool 30 having a groove 31. Recesses 33 ateach end of spool 30 receives compression springs 34 and 35,respectively. Compression spring 34 bears against stop ring 36 mountedto spindle l1, and compression spring 35 bears against the upper surfaceof machine 13. Shaft 37 is fastened to valve spool 30 and includes anenlarged head 38 disposed within cylindrical bore 39 of piston 26. Stopring 40 is fastened to piston 26 within bore 39 to engage the lowersurface of enlarged head 38.

Clevis 41 mounted to shafi portion 27 of piston 26 by means of pin 42.Seal means 43 provides a fluid seal to permit pressurizing region 59.The lowest surface of clevis 41 is adapted to contact the top surface ofhead 38 when piston 26 approaches its lowermost position and thusactuate valve 29.

Cam stator 44 is fastened to spindle l 1 by means of threaded fasteners45. Stator 44 closes the upper end of bore 25 within the spindle and issealed to spindle I l and shaft 37 by means of fluid seals 47 and 48respectively to permit pressurizing region 61. The arrangement of camstator 44 and housing 17 is such that a cavity 50 is formed betweenthem, which cavity contains ring spring 5] and ball bearing 52. Seals23, 46 and 49 provide a fluid seal between spindle ll and stator 4-4 oneach side to permit pressurizing cavity 50.

As shown particularly in FIG. 8 the lower surface of spindle 11 includesport openings 53, 54, 55 and 56. As shown in FIG. 1, port opening 53 isin fluid communication with valve port 57 which in turn is in fluidcommunication with groove 31 of spool 30. Port opening 54 is in fluidcommunication with port 58 which is in fluid communication with theupper port of valve 29 and with region 59 in cylinder 25 below piston26. Port opening 55 is in fluid communication with port 60 which in turnis in fluid communication with the lower port of valve 29 and withregion 61 in cylinder 25 above piston 26. Port opening 56 is in fluidcommunication with port 62 (FIG. 7) which in turn is in fluidcommunication with cavity 50 between cam stator 44 and housing 17. (Itis to be understood that the arrangement of the ports is preferably thesame as that illustrated in H0. 8, and that FIG. 1 shows in a differentposition for purposes of explanation).

Cam stator 44 includes symmetrical and opposite slots 63 and 64 whichtrack helically upwardly and counter-clockwise (as it would appear fromthe top) about axis 15. Rotor 65 is journaled to stator 44 by means ofball bearing 66 and includes slots 67 and 68 which track helicallyupwardly and clockwise (as it would appear from the top) about axis 15.Rod 69 is fastened to clevis 41 and includes rollers 70, 71, 72 and 73.Roller 70 is adapted to track within slot 63 of stator IOIMA m In 44,roller 71 is adapted to track within slot 64 of stator 44, roller 72 isadapted to track within slot 67 of rotor 65, and roller 73 is adapted totrack within slot 68 of rotor 65.

Upper housing 74 is fastened by means of ring 75 and threaded fasteners76 to lower housing 17. Plate 77 closes the top of housing 74 and isfastened thereto by means of threaded fasteners 78. Housing 74 includesslots 79 which are adapted to receive lugs 80 of coupling ring 81.Likewise, rotor 65 includes slots 82 which are adapted to receive lugs83 of coupling ring 81. The lugs of coupling ring 81 are received in theslots of housing 74 and rotor 65 so as to prevent relative rotation ofhousing 74 and rotor 65 about axis 15. it can be understood withreference to H6. 2 and 3 that surface 850 of lug 85 is located at aright angle to surface 880 of lug 88 and that surface 860 of lug 86 isat a right angle to surface 870 of lug 87. The arrangement is similar tothat of an Oldham coupling in order to avoid transmission of lateralforces between rotor 65 and housing 74. The clamp joint between theupper housing and the lower housing permits the rotation of the lowerhousing relative to the upper housing while setting up the machine,thereby permitting the cutting tools to be rotated to any desiredposition. Utilization of an intermediate adjustment, such as ring 84,permits the lower housing to be journaled directly to the center spindlewithout any intermediate members, thereby contributing to the rigidityand accuracy of the apparatus.

lndexing ring 84 has a first pair of lugs 85 and 86 projecting from thelower surface thereof and has a pair of lugs 87 and 88 projecting fromthe upper surface thereof. Stator 44 includes lugs 89 and 90 eachadapted to engage lugs 85 and 86 of indexing ring 84. Likewise, housing74 includes lugs 91 and 92 each adapted to engage lugs 87 and 88 byindexing ring 84.

The arrangement of indexing ring 84 to stator 44 and housing 74 is suchthat the indexing ring may rotate 90 with respect to the stator and 90with respect to the housing. Thus, and with particular reference toFIGS. 2 and 3, lock ring 84 may rotate 90 counter-clockwise with respectto stator 44 from the position shown in FIG. 2 (wherein lug 85 engageslug 89 and wherein lug 86 engages lug 90) to the position wherein lug 85engages lug 90 and lug 86 engages lug 89. At the same time, housing 74rotates the same 90 in the counter-clockwise direction because lugs 87and 88 on ring 84 bear against lugs 91 and 92 in housing 74. However,housing 74 may rotate an additional 90 in a counter-clockwise directionby rotating from the position illustrated in FIG. 3 (wherein lug 87engages lug 91 and lug 88 engages lug 92) to the position wherein lug 92engages lug 87 and lug 91 engages lug 88. Thus indexing ring 84 indexesthe position of housing 74 with respect to stator 44 to two positionsexactly 180 apart. It is to be understood that by varying the positionof the lugs, other angular increments are available. In this regard, theangular position may be varied merely by changing indexing ring 84 andreplacing it with one having a different lobe configuration.

The stop assembly is designed to be a self-aligning device thatequalizes the load of the stop lugs and produces no lateral forces. Tothis extent it has some of the characteristics of the Oldham coupling,in that the mating surfaces are arranged so as to be located at rightangles to each other. Ring 84 therefore acts as a torque stop only andnot as a center locating device. The two large lugs on ring 84 engagecorresponding lugs on cam stator 44. The lugs on the opposite face ofindex ing ring 84 engage lugs on the upper drive housing 74. One pair oflugs engages when rotating in one direction and the other pair of lugsengage when rotating in the opposite direction. The geometry is arrangedso as to place the mating stop surfaces at right angles to each other sothat the stop ring will be self-aligning and produce no radial forces.

Since spindle 11 is fixedly attached to machine tool 13, and sincestator 44 is fixedly attached to spindle 11, it can be un derstood thatthe housing 74 may be rotated about axis between the angular positionsdetermined by indexing ring 84. it can further be understood that sincehousing 17 is adjustably attached to housing 74 and that since toolholder 19 is fixedly attached to said housing 17, the tool holder, andthe tool attached thereto, is rotatable to predetermined indexed radialpositions about axis 15. Clamp ring 75 is provided so that theorientation of housing 17 may be adjusted thru 360 as required withrespect to index positions of housing 74.

Amuming it is desirable to move the tool attached to bracket 19 from theposition illustrated in FIG. 1 to a position 180 out of phase with thatshown in FIG. 1 (and at the same time, perhaps, move another toolmounted to housing 17 into position for operation on a workpiece),hydraulic fluid is applied through port opening 54 and port 58 to theupper portion of two-way valving means 29 and to the region 59 belowpiston 26. Piston 26 moves upwardly along axis 15 under the force of thefluid until stop ring 40 engages the lower surface of head 38. At thattime, continued upward travel of piston 26 pulls head 38 upwardlythereby drawing piston 30 upwardly to provide fluid communicationbetween port 58 and port 57 through the groove 31 of spool 30. Continuedapplication of pressurized fluid through port 58 causes pressurizedfluid to be expelled through the port opening 53 and port 57. At thesame time, any fluid above piston 26 in cylinder 25 is expelled throughport 60.

As piston 26 travels upwardly, it can'ies with it rod 69 and the rollers70-73 which are engaged to the slots on stator 44 and rotor 65. As rod69 travels upwardly, and since the stator is stationary, cams 70 and 71in the cam followers on stator 44 will track counter-clockwise therebyrotating rod 69 in a counter-clock-wise direction. The axial thrust isaccommodated by bearing 66. As rod 69 rotates counter-clockwise, itcarries with it the rotor. However, because the rotor has clockwisehelical slots the rotor 65 will tend to rotate counterclockwise due toupward movement of rod 69. Hence, rotor 65 rotates counter-clockwisewith respect to the stator by virtue of the counter-clockwise rotationof rod 69, and additionally, by virtue of its own cam follower pattern.Since the slots are each sized to permit more than travel (93 beingpreferrable), rotor 65 will rotate about 90 due to the upwardly movementof rod 69, and will rotate an additional 90 on the rod. Hence, the rotorrotates 180 from the position illustrated in the drawing to a position180 out of phase as determined by indexing ring 84 as heretoforedescribed.

When piston 26 reaches near its full upwardly travel, stop ring 40 drawshead 38 upwardly, thereby moving spool 30 of valving means to itsuppermost position. Pressurized fluid from port 58 passes through thepassage provided by groove 31, port 57 and is emitted through portopening 53 as heretofore described. Pressurized fluid appearing at portopening 53 operates valve 114 in FIG. 9 to cause pressurized fluid to beapplied to port opening 56 thereby causing pressurized fluid to flowthrough port 62 (FIGS. 7 and 8) to cavity 50 between stator 44 androtatable housing 17. The pressurized fluid in cavity 50 causes housing17 to move downwardly so that surface 21 on member 20 bears againstsurface 16 on spindle 11 to clamp housing 17 against spindle 11. Theclamping force in cavity 50 is determined by the surface area of cavity50 on housing 17 and the pressure of the fluid. The force is transmittedthrough housing 17 and member 20 to cause the surfaces 16 and 21 to bearagainst each other thereby clamping housing 16 against the spindlethereby preventing the housing from rotating about axis 15.

FIG. 9 illustrates a schematic diagram of a hydraulic and electriccircuit for operating the tool holder in accordance with the presentinvention. As shown in FIG. 9, pump is connected to reservoir 101 todeliver pressurized hydraulic fluid to line 102. Line 102 is connectedthrough delay restrictor 104 to one side of two-position valve 105. Thearrangement of two-position valve 105 is such that when in the positionillustrated in FIG. 9, pressurized fluid is delivered through the valveto line 106 and fluid in line 107 is relieved through valve 105 toreservoir 108. in the second position of valve 105, pressurized fluid isdelivered through the valve to line 107 and line 106 is relieved toreservoir 108. Solenoid 109 is provided for selectively positioningtwo-way valve 105. Solenoid 109 is connected via leads 110 and 111 to acontrol panel (not shown) from which it may be controlled. Line 106 isconnected to port 58 of holder 10, port 58 being connected to the region59 beneath piston 26. Line 107 is connected to port 55 throughrestrictor 112, port 55 being connected to the region 61 above piston26.

To move the piston from its lower to its upper position (and therebymoving the tools mounted to the holder 180), pressurized fluid isapplied through line 106 and port 58 to the region 59 beneath the pistonthereby forcing the piston upwardly and driving any fluid in region 61through line 107 to the reservoir 108. The housing rotates until theindexed position is reached as determined by indexing ring 84 (FIG. 1 Itis undesirable to permit the tool holder to clamp down the wrong portionof the stroke of the piston. Therefore, a pilot valve is provided withinthe tool holder which responds to the position of the piston to actuatethe clamp. Head 38 engages the ring carried by piston 26 thereby drawingspool 30 of valve 29 upwardly. When spool 30 is in its upper position,line 106 provides fluid communication through port 53 to pilot line 113to operate on two-way valve 114.

Valve 114 is a two-position, spring-loaded valve depressurized when line115, which is connected to pressurized line 102, is blocked, and line116 is in fluid communication with reservoir 117. In the second positionof valve 114, line 115 is in fluid communication with line 116. Line 116is connected via restrictor 118 to port 56 of the tool holder. Port 56is in fluid communication with cavity 50 as heretofore explained.

When pressurized fluid is applied to pilot line 113, such as by movingspool 30 of valving means 29 to its uppermost position to provide fluidcommunication between lines 106 and 113 when line 106 is pressurized.valve 114 is moved to its second position under the influence of thepressure of the fluid in line 113 thereby providing fluid communicationbetween line 115 and 116 to apply fluid pressure to cavity 50. Thepressurized fluid in cavity 50 clamps the tool holder as heretoforedescribed. At the same time, pressurized fluid on line 116 operatespressure switch 119 to provide an electric signal via lead 120 to theoperator's control panel to operate an indicator (not shown) indicativethat the clamping operation has been accomplished.

When rotating normally, the pressure required to operate the tool holdermay be quite small, and most of the pressure differential appears acrossthe orifice between the supply line and the actuators. When the indexingstroke is complete, however, the piston offers resistance to furtherflow of fluid so that the pressure across the orifice is removed and thepressure on the high side of the piston approaches that of the supply.The pressure on the high side of the piston is vented through the pilotactuator line 1 13 to operate the pressure-operated valve.

When it is desirable to return piston 26 to a downward position, therebyreturning the work tool to the position illustrated in F 1G. 1, thecontroller operates a switch on the control panel (not shown) whichoperates solenoid 109 via leads 110 and 111 to shift the position ofvalve 105 to its second position thereby applying pressurized fluid toline 107 and relieving pressurized fluid from line 106. The pressure inline 113, which has been in fluid communication with line 106, is alsorelieved to reservoir 108 through valve 105 thereby relieving thepressure on valve 114 and permitting the spring therein to return thevalve to its depressu rized position illustrated in FIG. 9. With valve114 in its depressurized position, the pressure in cavity 50 is relievedthrough line 116 to reservoir 117 thereby declamping the tool holder. Atthe same time, the pressure on pressure switch 119 is relieved therebyproviding a signal at the operators panel via leads 120 indicative thatthe declamping operation has been accomplished.

As pressurized fluid is applied through line 107 to region 61 aboutpiston 26, the piston moves downwardly to rotate the housing back to theposition shown in FIG. 1. The spring biasing piston 30 returns thepiston to its neutral position shown in FIG. 9. As piston 26 continuesits downward travel, fluid in region 59 is expelled ahead of the pistonthrough line 106 to reservoir 108. The operation continues until piston26 has traveled substantially its full length and the bottom of clevis42 bears against head 38 hereby driving piston 30 downwardly to thesecond position. When in the second position of piston 30, pressurizedfluid in line 107 is connected via port 53 to pilot line 113 to againoperate on valve 114 to apply pressurized fluid via line 1 16 toclamping cavity 50, thereby clamping the arrangement as heretoforedescribed.

The present invention thus provides a two-position indexing tool holderwherein a work tool may be moved into and out of position for operationon a workpiece. The apparatus is effective in operation, and requireslittle maintenance. One feature of the invention resides in the factthat the indexing ring for indexing the extreme positions of the toolholder may be changed so that other indexing rings may index theapparatus to different angular positions. Thus, although the presentinvention describes a two-position tool holder wherein the tool is moveddifferent indexing rings 84 with different lobe configuration can beused so that angular displacement between the extreme radial positionsof the tool may be selectively altered.

The tool holder according to the present invention provides an effectivemeans for moving a work tool into and out of position for operation on aworkpiece and wherein the tool is fixedly positioned in its extremepositions by means of a clamp. The hydraulic circuit associated with thepresent invention provides an operative system for operating the toolholder so that the same may be easily controiied. The control circuitalso provides an indication of the operation of the tool holder.

Work tools may be positioned on opposite sides of housing 17 so thatthey may be successively moved into and out of position for operation onthe workpiece, so that the machine is not required to be shut down inorder to change the tools. Hence, loss of time of operation of themachine is minimized and the machine may be fully exploited.Furthermore, the operator need not devote as much time to operation ofthe machine and changing of work tools for each machine, so that asingle operator can handle more machines, thereby increasing productionrates.

This invention is not to be limited by the embodiment shown in thedrawings and described in the description, which is given by way ofexample and not of limitation, but only in accordance with the scope ofthe appended claims.

What is claimed is:

l. A multi-position tool holder comprising: spindle means having an axisand adapted to be mounted to a machine; housing means joumaled to saidspindle means for movement between first and second radial positions;mount means carried by said housing means for supporting a tool; drivemeans for rotating said housing means between said first and secondangular positions, said drive means comprising rotor means attached tosaid housing, piston means adapted to reciprocate along said axisbetween a first and a second axial position, and cam and cam followermeans interlinking said rotor means and said piston means, said cam andcam follower means being so arranged and disposed as to rotate saidrotor means about said axis to rotate said housing means between itsfirst and second angular position when said piston means is movedbetween its first and second axial positions, respectively; and clampmeans for preventing relative rotation between said housing means andsaid spindle means when said housing means is in either its first or itssecond angular position, said clamp means comprising a first clampsurface on said housing means and a second clamp surface on said spindlemeans, and responsive means responsive to the position of said pistonmeans to cause said first and second clamp surfaces to bear against eachother when said piston means is in either its first or second axialposition; stator means mounted to said spindle means and having secondcam follower means, said cam follower means being carried by said rotormeans and said cam means being carried by said piston means, said cammeans being adapted to track in said second cam follower means as saidpiston reciprocates between its first and second axial positions; andindexing means comprising ring means having first lug means adapted toengage stator lug means on said stator means and second lug meansadapted to engage rotor lug means on said rotor'means, said first,second, stator lug means and rotor lug means being so arranged anddisposed relative to each other as to limit the rotational travel ofsaid rotor means about said axis and thereby defining said first andsecond angular positions of said housing means.

2. Apparatus according to claim 1 wherein said clamp means furtherincludes an annular cavity between said stator means and said housingmeans, and said responsive means includes a source of pressurized fluidand piston-operable valve means responsive to the position of saidpiston means to provide fluid communication between said source ofpressurized fluid and said annular cavity when said piston means is inits first and second axial positions.

3. Apparatus according to claim 2 further including fluid handling meansfor selectively connecting said source of pressurized fluid to oppositesides of said piston means to move said piston means between its firstand second axial positions.

4. Apparatus according to claim 3 wherein said fluid handling meansincludes first valving means having a first position wherein said sourceof pressurized fluid is in fluid communication with one side of saidpiston means and pressure on the other side of said piston means isrelieved, and a second position wherein said source of pressurized fluidis in fluid communication with said other side of said piston means andthe pressure on said one side of said piston means is relieved, andsecond valving means having a first position wherein the pressure insaid cavity is relieved and having a second position connecting saidsource of pressurized fluid to said cavity, a pilot line connected tosaid second valving means to move said second valving means to itssecond position when said pilot line contains pressurized fluid and tomove said second valving means to its first position when pressure isrelieved from said pilot line, said piston-operable valve meansproviding fluid communication between said one side of said piston meansand said pilot line when said piston means is in its first axialposition, and between said other side of said piston means and saidpilot line when said piston means is in its second axial position, saidpiston-operable valve means being further adapted to relieve thepressure in said pilot line when said piston means is between its firstand second axial positions, whereby upon movement of said first valvingmeans to its second position pressurized fluid is admitted to said otherside of said piston means thereby moving said piston means to its secondaxial position whereupon pressurized fluid is applied to said pilot lineto move said second valving means to its second position therebyadmitting pressurized fluid into said cavity to cause said first andsecond clamp surfaces to bear against each other, and whereby uponmovement of said first valving means from its second to its firstposition pressurized fluid on said other side of said piston means andon said pilot line is relieved, thereby moving said second valving meansto its first position to relieve pressurized fluid from said cavity andpressurized fluid is applied to said one side of said piston means tomove said piston means to its first axial position to rotate saidhousing from its second to its first radial position, and wherebypressurized fluid is applied to said pilot line when said piston meansreaches its first axial position to move said second valving means toits second position, thereby admitting pres- All" surized fluid intosaid cavity to cause said first and second clamp surfaces to bearagainst each other.

5. Apparatus according to claim 4 further including controller means formoving said first valving means between its first and second positions.

6. A two-position indexing tool holder comprising: a spindle having anaxis; means for fastening said spindle to a machine; a cylinder in saidspindle; a piston reciprocably mounted in said cylinder for movementbetween first and second positions; a valve element in said spindle;first and second stop means adapted to engage said piston to move saidvalve element to first and second positions when said piston is in itsfirst and second positions, respectively, and to a neutral position whensaid piston is between its first and second axial positions; a housingjournaled to said spindle for rotation about said axis; clamp meansresponsive to the position of said valve element to clamp said housingagainst said spindle when said valve element is in either its first orits second position; a stator fixedly attached to said spindle andcarrying first cam follower means; a rotor joumaled to said stator andcarrying second cam follower means; attachment means attaching saidrotor to said housing; cam means carried by said piston and engagingsaid first and second cam follower means, said cam means and first andsecond cam follower means being so disposed and arranged that uponmovement of said piston between its first and second positions said cammeans tracks in said first cam follower means to rotate said pistonabout said axis thereby rotating said rotor about said axis to rotatesaid housing about said axis between first and second radial positions,respectively; and means on said housing for carrying a work tool.

7. Apparatus according to claim 6 further including an indexing ringbetween said stator and said rotor for limiting the extent of rotationaltravel between the stator and the rotor, thereby defining the locationof said first and second radial positions of said housing.

8. Apparatus according to claim 6 wherein said clamp means comprisesclamp surfaces on said housing and on said spindle adapted to bearagainst each other, and an annular cavity between said stator and saidhousing so disposed and arranged that when pressurized fluid is appliedto said cavity said clamp surfaces bear against each other.

9. Apparatus according to claim 8 further including a first port influid communication with said cylinder on one side of said piston andwith said valve element when in its first position, a second port influid communication with said cylinder on the opposite side of saidpiston and with said valve element when in its second position, a thirdport in fluid communication with said valve element in all of itspositions, a fourth port in fluid communication with said cavity, andfluid handling means responsive to pressurized fluid at said third portmeans to apply pressurized fluid to said fourth port means, whereby uponapplication of pressurized fluid to said first port said piston is movedto its first position and upon application of pressurized fluid to saidsecond port said piston is moved to its second position.

l0. Apparatus according to claim 9 further including an indexing ringbetween said stator and said rotor for limiting the extent of rotationaltravel between the stator and the rotor, thereby defining the locationof said first and second radial positions of said housing.

UNITED STATES PATENT OFFICE Patent No.

Dated 675.519 July 1 1 1972 Inventor-(s) It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Col, line Col. line Col. line Col. line Col. line Col. line Col. lineCol. line [SEAL] 13 has" should read --had-- 37 after "41" insert --is--17 "piston" should read -spool-- 29 "counter-clock-wise" should read--counter-clockwise-- 71 change "about" to --above-- 72 "spring" shouldread --springs-- 73 change "piston" to --spool-- 73 change "returns" to--return-- 3 "hereby" should read --thereby-- 3 "piston" should read--spool-- 4 "piston" should read --spool-- Signed and Sealed thisTwenty-sixth D3) of October 1976 Arresr:

RUTH C. MASON Arresting Officer

1. A multi-position tool holder comprising: spindle means having an axisand adapted to be mounted to a machine; housing means journaled to saidspindle means for movement between first and second radial positions;mount means carried by said housing means for supporting a tool; drivemeans for rotating said housing means between said first and secondangular positions, said drive means comprising rotor means attached tosaid housing, piston means adapted to reciprocate along said axisbetween a first and a second axial position, and cam and cam followermeans interlinking said rotor means and said piston means, said cam andcam follower means being so arranged and disposed as to rotate saidrotor means about said axis to rotate said housing means between itsfirst and second angular position when said piston means is movedbetween its first and second axial positions, respectively; and clampmeans for preventing relative rotation between said housing means andsaid spindle means when said housing means is in either its first or itssecond angular position, said clamp means comprising a first clampsurface on said housing means and a second clamp surface on said spindlemeans, and responsive means responsive to the position of said pistonmeans to cause said first and second clamp surfaces to bear against eachother when said piston means is in either its first or second axialposition; stator means mounted to said spindle means and having secondcam follower means, said cam follower means being carried by said rotormeans and said cam means being carried by said piston means, said cammeans being adapted to track in said second cam follower means as saidpiston reciprocates between its first and second axial positions; andindexing means comprising ring means having first lug means adapted toengage stator lug means on said stator means and second lug meansadapted to engage rotor lug means on said rotor means, said first,second, stator lug means and rotor lug means being so arranged anddisposed relative to each other as to limit the rotational Travel ofsaid rotor means about said axis and thereby defining said first andsecond angular positions of said housing means.
 2. Apparatus accordingto claim 1 wherein said clamp means further includes an annular cavitybetween said stator means and said housing means, and said responsivemeans includes a source of pressurized fluid and piston-operable valvemeans responsive to the position of said piston means to provide fluidcommunication between said source of pressurized fluid and said annularcavity when said piston means is in its first and second axialpositions.
 3. Apparatus according to claim 2 further including fluidhandling means for selectively connecting said source of pressurizedfluid to opposite sides of said piston means to move said piston meansbetween its first and second axial positions.
 4. Apparatus according toclaim 3 wherein said fluid handling means includes first valving meanshaving a first position wherein said source of pressurized fluid is influid communication with one side of said piston means and pressure onthe other side of said piston means is relieved, and a second positionwherein said source of pressurized fluid is in fluid communication withsaid other side of said piston means and the pressure on said one sideof said piston means is relieved, and second valving means having afirst position wherein the pressure in said cavity is relieved andhaving a second position connecting said source of pressurized fluid tosaid cavity, a pilot line connected to said second valving means to movesaid second valving means to its second position when said pilot linecontains pressurized fluid and to move said second valving means to itsfirst position when pressure is relieved from said pilot line, saidpiston-operable valve means providing fluid communication between saidone side of said piston means and said pilot line when said piston meansis in its first axial position, and between said other side of saidpiston means and said pilot line when said piston means is in its secondaxial position, said piston-operable valve means being further adaptedto relieve the pressure in said pilot line when said piston means isbetween its first and second axial positions, whereby upon movement ofsaid first valving means to its second position pressurized fluid isadmitted to said other side of said piston means thereby moving saidpiston means to its second axial position whereupon pressurized fluid isapplied to said pilot line to move said second valving means to itssecond position thereby admitting pressurized fluid into said cavity tocause said first and second clamp surfaces to bear against each other,and whereby upon movement of said first valving means from its second toits first position pressurized fluid on said other side of said pistonmeans and on said pilot line is relieved, thereby moving said secondvalving means to its first position to relieve pressurized fluid fromsaid cavity and pressurized fluid is applied to said one side of saidpiston means to move said piston means to its first axial position torotate said housing from its second to its first radial position, andwhereby pressurized fluid is applied to said pilot line when said pistonmeans reaches its first axial position to move said second valving meansto its second position, thereby admitting pressurized fluid into saidcavity to cause said first and second clamp surfaces to bear againsteach other.
 5. Apparatus according to claim 4 further includingcontroller means for moving said first valving means between its firstand second positions.
 6. A two-position indexing tool holder comprising:a spindle having an axis; means for fastening said spindle to a machine;a cylinder in said spindle; a piston reciprocably mounted in saidcylinder for movement between first and second positions; a valveelement in said spindle; first and second stop means adapted to engagesaid piston to move said valve element to first and second positionswhen said piston is in its first and second positions, respectively, andto a neutral position when said piston is between its first and secondaxial positions; a housing journaled to said spindle for rotation aboutsaid axis; clamp means responsive to the position of said valve elementto clamp said housing against said spindle when said valve element is ineither its first or its second position; a stator fixedly attached tosaid spindle and carrying first cam follower means; a rotor journaled tosaid stator and carrying second cam follower means; attachment meansattaching said rotor to said housing; cam means carried by said pistonand engaging said first and second cam follower means, said cam meansand first and second cam follower means being so disposed and arrangedthat upon movement of said piston between its first and second positionssaid cam means tracks in said first cam follower means to rotate saidpiston about said axis thereby rotating said rotor about said axis torotate said housing about said axis between first and second radialpositions, respectively; and means on said housing for carrying a worktool.
 7. Apparatus according to claim 6 further including an indexingring between said stator and said rotor for limiting the extent ofrotational travel between the stator and the rotor, thereby defining thelocation of said first and second radial positions of said housing. 8.Apparatus according to claim 6 wherein said clamp means comprises clampsurfaces on said housing and on said spindle adapted to bear againsteach other, and an annular cavity between said stator and said housingso disposed and arranged that when pressurized fluid is applied to saidcavity said clamp surfaces bear against each other.
 9. Apparatusaccording to claim 8 further including a first port in fluidcommunication with said cylinder on one side of said piston and withsaid valve element when in its first position, a second port in fluidcommunication with said cylinder on the opposite side of said piston andwith said valve element when in its second position, a third port influid communication with said valve element in all of its positions, afourth port in fluid communication with said cavity, and fluid handlingmeans responsive to pressurized fluid at said third port means to applypressurized fluid to said fourth port means, whereby upon application ofpressurized fluid to said first port said piston is moved to its firstposition and upon application of pressurized fluid to said second portsaid piston is moved to its second position.
 10. Apparatus according toclaim 9 further including an indexing ring between said stator and saidrotor for limiting the extent of rotational travel between the statorand the rotor, thereby defining the location of said first and secondradial positions of said housing.